diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_builtin.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_builtin.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c new file mode 100644 index 00000000000..7cde8a66520 --- /dev/null +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -0,0 +1,214 @@ +/* + * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + */ + +#include <linux/cpu.h> +#include <linux/kvm_host.h> +#include <linux/preempt.h> +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/bootmem.h> +#include <linux/init.h> +#include <linux/memblock.h> +#include <linux/sizes.h> + +#include <asm/cputable.h> +#include <asm/kvm_ppc.h> +#include <asm/kvm_book3s.h> + +#include "book3s_hv_cma.h" +/* + * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206) + * should be power of 2. + */ +#define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */ +/* + * By default we reserve 5% of memory for hash pagetable allocation. + */ +static unsigned long kvm_cma_resv_ratio = 5; +/* + * We allocate RMAs (real mode areas) for KVM guests from the KVM CMA area. + * Each RMA has to be physically contiguous and of a size that the + * hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB, + * and other larger sizes. Since we are unlikely to be allocate that + * much physically contiguous memory after the system is up and running, + * we preallocate a set of RMAs in early boot using CMA. + * should be power of 2. + */ +unsigned long kvm_rma_pages = (1 << 27) >> PAGE_SHIFT; /* 128MB */ +EXPORT_SYMBOL_GPL(kvm_rma_pages); + +/* Work out RMLS (real mode limit selector) field value for a given RMA size. + Assumes POWER7 or PPC970. */ +static inline int lpcr_rmls(unsigned long rma_size) +{ + switch (rma_size) { + case 32ul << 20: /* 32 MB */ + if (cpu_has_feature(CPU_FTR_ARCH_206)) + return 8; /* only supported on POWER7 */ + return -1; + case 64ul << 20: /* 64 MB */ + return 3; + case 128ul << 20: /* 128 MB */ + return 7; + case 256ul << 20: /* 256 MB */ + return 4; + case 1ul << 30: /* 1 GB */ + return 2; + case 16ul << 30: /* 16 GB */ + return 1; + case 256ul << 30: /* 256 GB */ + return 0; + default: + return -1; + } +} + +static int __init early_parse_rma_size(char *p) +{ + unsigned long kvm_rma_size; + + pr_debug("%s(%s)\n", __func__, p); + if (!p) + return -EINVAL; + kvm_rma_size = memparse(p, &p); + /* + * Check that the requested size is one supported in hardware + */ + if (lpcr_rmls(kvm_rma_size) < 0) { + pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size); + return -EINVAL; + } + kvm_rma_pages = kvm_rma_size >> PAGE_SHIFT; + return 0; +} +early_param("kvm_rma_size", early_parse_rma_size); + +struct kvm_rma_info *kvm_alloc_rma() +{ + struct page *page; + struct kvm_rma_info *ri; + + ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL); + if (!ri) + return NULL; + page = kvm_alloc_cma(kvm_rma_pages, kvm_rma_pages); + if (!page) + goto err_out; + atomic_set(&ri->use_count, 1); + ri->base_pfn = page_to_pfn(page); + return ri; +err_out: + kfree(ri); + return NULL; +} +EXPORT_SYMBOL_GPL(kvm_alloc_rma); + +void kvm_release_rma(struct kvm_rma_info *ri) +{ + if (atomic_dec_and_test(&ri->use_count)) { + kvm_release_cma(pfn_to_page(ri->base_pfn), kvm_rma_pages); + kfree(ri); + } +} +EXPORT_SYMBOL_GPL(kvm_release_rma); + +static int __init early_parse_kvm_cma_resv(char *p) +{ + pr_debug("%s(%s)\n", __func__, p); + if (!p) + return -EINVAL; + return kstrtoul(p, 0, &kvm_cma_resv_ratio); +} +early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv); + +struct page *kvm_alloc_hpt(unsigned long nr_pages) +{ + unsigned long align_pages = HPT_ALIGN_PAGES; + + /* Old CPUs require HPT aligned on a multiple of its size */ + if (!cpu_has_feature(CPU_FTR_ARCH_206)) + align_pages = nr_pages; + return kvm_alloc_cma(nr_pages, align_pages); +} +EXPORT_SYMBOL_GPL(kvm_alloc_hpt); + +void kvm_release_hpt(struct page *page, unsigned long nr_pages) +{ + kvm_release_cma(page, nr_pages); +} +EXPORT_SYMBOL_GPL(kvm_release_hpt); + +/** + * kvm_cma_reserve() - reserve area for kvm hash pagetable + * + * This function reserves memory from early allocator. It should be + * called by arch specific code once the early allocator (memblock or bootmem) + * has been activated and all other subsystems have already allocated/reserved + * memory. + */ +void __init kvm_cma_reserve(void) +{ + unsigned long align_size; + struct memblock_region *reg; + phys_addr_t selected_size = 0; + /* + * We cannot use memblock_phys_mem_size() here, because + * memblock_analyze() has not been called yet. + */ + for_each_memblock(memory, reg) + selected_size += memblock_region_memory_end_pfn(reg) - + memblock_region_memory_base_pfn(reg); + + selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT; + if (selected_size) { + pr_debug("%s: reserving %ld MiB for global area\n", __func__, + (unsigned long)selected_size / SZ_1M); + /* + * Old CPUs require HPT aligned on a multiple of its size. So for them + * make the alignment as max size we could request. + */ + if (!cpu_has_feature(CPU_FTR_ARCH_206)) + align_size = __rounddown_pow_of_two(selected_size); + else + align_size = HPT_ALIGN_PAGES << PAGE_SHIFT; + + align_size = max(kvm_rma_pages << PAGE_SHIFT, align_size); + kvm_cma_declare_contiguous(selected_size, align_size); + } +} + +/* + * When running HV mode KVM we need to block certain operations while KVM VMs + * exist in the system. We use a counter of VMs to track this. + * + * One of the operations we need to block is onlining of secondaries, so we + * protect hv_vm_count with get/put_online_cpus(). + */ +static atomic_t hv_vm_count; + +void kvm_hv_vm_activated(void) +{ + get_online_cpus(); + atomic_inc(&hv_vm_count); + put_online_cpus(); +} +EXPORT_SYMBOL_GPL(kvm_hv_vm_activated); + +void kvm_hv_vm_deactivated(void) +{ + get_online_cpus(); + atomic_dec(&hv_vm_count); + put_online_cpus(); +} +EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated); + +bool kvm_hv_mode_active(void) +{ + return atomic_read(&hv_vm_count) != 0; +} |